1. Field of the Invention
The present invention relates to a shooting lens for reducing a vibration of an image of a subject and a camera system therefor.
2. Description of the Related Art
There has been a known technique for driving a vibration reduction mechanism to reduce a vibration of an image of a subject due to a hand vibration or the like. Such a known technique includes a vibration reduction mechanism (such as an optical vibration reduction system or the like) and an angular speed sensor. The angular speed sensor detects vibration of a shooting lens and of a camera. The shooting lens decides, from the angular speed, the position of the vibration reduction mechanism to eliminate the vibration of the image (hereinafter referred to as target drive position), and moves the vibration reduction mechanism to the target drive position.
In addition, the shooting lens executes a positional control over the vibration reduction mechanism, moving it back to the center position (hereinafter referred to as center bias control), by feeding back the displacement thereof to the control over the vibration reduction mechanism. The center bias control allows the vibration reduction mechanism to be moved back to the vicinity of the center position thereof. As a result, it is possible to substantially expand the moving range of the vibration reduction mechanism.
Japanese Unexamined Patent Application Publication No. Hei 10-322585 (FIG. 1) (Reference 1) and 10-145662 (FIG. 1 and FIG. 3) (Reference 2) have disclosed an image vibration reduction technique for a video camera. The video camera detects a motion signal from a captured image. Then, the video camera interpolates the motion signal to raise the sampling grade thereof. The video camera improves the vibration reduction performance by feeding back the interpolated motion signal to a target drive position that is updated at high speed.